JP2001340708A - Equipment and process for filtration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive and simple filtration equipment in which the performance of a filtration member can be maintained for a long period and also can surely be restored by backwashing, and also to provide a filtration process using the filtration equipment. SOLUTION: This equipment is provided with: a treatment vessel 2 which has within it hollow fiber membrane filters 7 and into which raw water is introduced; a siphon pipe 5 which is connected to the bottom of the treatment vessel 2 and rises so as to form an inverted-U shape; and a suction pump 4 which is connected to the outlet side of each of the filters 7 and used for the purpose of sucking a treated liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inexpensive and simple filtration apparatus and a filtration method capable of maintaining the performance of a filtration member for a long period of time and reliably restoring the performance by backwashing.

[0002]

2. Description of the Related Art In the production of laver, for example, laver is supplied to a fully automatic laver maker after a seawater treatment step and a freshwater treatment step, and laver is obtained from water containing laver. Specifically, the laver after the freshwater treatment is supplied to a sheeting section of an automatic laver manufacturing apparatus equipped with a laver cage to form laminar laver. On the other hand, the water recovered from the papermaking section
Used many times cyclically.

[0003]

The seaweed supplied to the automatic seaweed manufacturing apparatus contains a lot of bacteria and diatoms in addition to the seaweed. Bacteria and the like will be concentrated by repeatedly using the collected liquid. Therefore, in order to cope with such a problem, there is a need for a simple and inexpensive, yet accurate, filtration device capable of removing even fine substances.

[0004] Such a filtration device is not limited to an automatic laver production device, but is also required in many other fields. However, the filtration device is liable to be clogged due to the capture of fine substances. Is a major issue.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides an inexpensive and simple filter that can maintain the performance of a filter member that is easily clogged for a long time and can surely restore the performance by passing water in the opposite direction. It is an object of the present invention to provide a filtering device and a filtering method.

[0006]

According to a first aspect of the present invention, there is provided a filtration apparatus including a processing tank provided with a filtering member therein, into which a liquid to be processed is introduced, and a bottom portion of the processing tank. It is characterized by a siphon tube which is connected and rises in an inverted U-shape, and a suction pump which is connected to an output side of the filtering member and sucks a processing liquid. In the present invention, since the filtration operation is performed by suctioning the outlet side of the filtration member, clogging does not occur in a short time even with the liquid to be treated having a large amount of turbid matter. The use of the filtration device of the present invention is not limited, but it is preferable to use it as a sheet water purifier for laver production.

Further, in the present invention, the bottom of the processing tank is provided with an inverted U
It is connected to a siphon tube that rises in the shape of a letter. Therefore, for example, when the treatment liquid reaches the top of the siphon tube when the treatment liquid reaches the top of the siphon tube when the treatment liquid is circulated in the reverse direction, the liquid in the treatment tank is automatically discharged. . Therefore, by performing such processing as needed, the performance of the filtering member can be easily restored to the initial state.

According to a second aspect of the present invention, there is provided a filtration device including a processing tank provided with a filtering member therein for introducing a liquid to be processed, a siphon tube connected to a bottom of the processing tank and rising in an inverted U-shape, A suction pump connected to the output side of the filtration member for sucking the processing liquid, a storage tank provided downstream of the suction pump, and an on-off valve provided downstream of the storage tank. ing. In the present invention, since the storage tank and the on-off valve are provided, the processing liquid can be stored in the storage tank by closing the on-off valve first. Therefore, the filtration member can be back-washed using this treatment liquid. Note that the storage tank is preferably a pressure tank in which the processing liquid is stored while contracting the contractible gas chamber. In this case, the above-described pressurization in the introduction direction with respect to the pressure tank is simply released. A reverse cleaning operation can be realized.

In the cleaning method according to a fourth aspect of the present invention, in a treatment tank having a filter member built-in and a siphon tube rising in an inverted U shape connected to a bottom portion, the water to be treated is output from the output side of the filter member. Filtration step of constantly sucking,
When the filter member needs to be washed, a transfer step of introducing treated water into the storage tank provided on the downstream side of the processing tank while contracting a gas chamber inside the storage tank, Thereafter, the operation of suctioning the output side of the filtration member is stopped, and the treated water introduced into the storage tank is returned to the treatment tank from the output side of the filtration member in the backwashing step.
The backwashing step is characterized by a step of raising the water level of the processing tank to communicate the flow path of the siphon tube, and thereafter discharging the liquid in the processing tank.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in more detail with reference to embodiments. FIG. 1 illustrates a microfiltration unit (a laver producing water purifier) according to the present embodiment, and is a plan view (a), a front view (b), a left side view (c), and a right side view. FIG. FIG. 2 is a flowchart showing a use state of the microfiltration unit 1 of FIG.

As shown in FIG. 1, a filtration unit 1 includes a processing tank 2 disposed at an upper front part of the unit, a pressure tank 3 disposed at a lower part of the processing tank 2, and a filter tank 3 disposed at a right front side of the pressure tank 3. Suction pump 4 and a siphon pipe 5 communicating with the bottom of the processing tank 2 at a position above the suction pump 4.
And two bag filters 6a and 6b arranged at the back of the processing tank 2.

The processing tank 2 has four hollow fiber membrane filters 7.
7, which receives raw water from the back filter 6b from the water supply port G and realizes a precise filtering operation in parallel. Level switches 8H and 8L for detecting the limit position of the float moving with the water surface are provided on the wall surface of the processing tank 2, and the water level of the processing tank 2 is adjusted by opening and closing the first solenoid valve 9 provided in the upstream flow path. It is maintained within a certain range. The outlet H of the processing tank 2 is connected to a suction pump 4, and the operation of the suction pump 4 sucks raw water in the processing tank 2.

At the bottom of the processing tank 2, there are provided four insertion ports (not shown) corresponding to the outlets of the hollow fiber membrane cartridges 7,..., Each of which communicates with a water collecting pipe. To the outlet H of the treatment tank. The top of each of the hollow fiber membrane cartridges 7 is held by a pressing plate 10 fixed to the wall surface of the processing tank 2 by sliding movement.

A shrinkable air chamber is provided inside the pressure tank 3. When pressure is applied in the direction of introducing the treated water, the treated water is introduced while the air chamber is contracted. On the other hand, when the pressure in the introduction direction is released, the treated water is discharged by the expansion operation of the air chamber. A pressure gauge 11 and a second solenoid valve 12 are provided downstream of the pressure tank 3. Then, when the second solenoid valve 12 is closed while the suction pump 4 is operating, the treated water is stored in the pressure tank 3 accordingly.
1 to know.

Next, the operation of the filtration unit 1 having the above configuration will be described. Here, in the production of laver, for example, the case where water after purifying laver is purified is exemplified.

At the time of steady operation, at the time of steady operation, the solenoid valve 9
The electromagnetic valve 12 is also in an open state, and the raw water in the nori last tank 13 is purified in a process of being circulated as indicated by the arrow in FIG. That is, the raw water in the nori last tank 13 is first supplied to the back filters 6a and 6b by the submersible pump 14, but the submersible pump 14 and the bag filter 6a are detachably formed by the male part M and the female part F. They are connected by a one-touch coupler 17. In this embodiment, the bag filter 6 is a disposable product having a structure for trapping a filtered substance in a bag. However, the bag filter 6a captures 50 μ or more, and the bag filter 6b captures 1 μ or more. Designed to be.

The raw water that has been subjected to the pretreatment by the back filters 6a and 6b is introduced into the treatment tank 2 from the water supply port G. The water level is controlled by the level switches 8H and 8L and the first solenoid valve 9. On the other hand, the outlet H of the processing tank 2
Since the raw water is sucked by the suction pump 4, the raw water introduced into the treatment tank 2 is filtered in the process of moving from the outside of the hollow fiber membrane to the hollow part. At this time, instead of pressurizing the outside of the hollow fiber membrane, the hollow part is sucked,
It is difficult to clog the outer surface of the thread membrane. Then, the treated water filtered in the treatment tank 2 passes through the detachable one-touch coupler 18 composed of the male part M and the female part F and passes through the nori final tank 1
Returned to 3.

[Backwashing operation] If the above-mentioned filtering operation is continued, a clogged state will be eventually formed. Therefore, the backwashing operation is performed at an appropriate timing (for example, periodically), and the hollow fiber membrane cartridges 7. It is necessary to dispose of the trapped fines. To realize the backwash operation, first, the second solenoid valve 12 is closed. In this case as well, the suction pump 4 is kept operating, so that the treated water after the filtration treatment is stored in the pressure tank 3.

Thereafter, at an appropriate timing, the suction pump 4
Is stopped, and the first solenoid valve 9 is also closed. Then
The treated water stored in the pressure tank 3 flows through the stopped suction pump 4 in the reverse direction, and flows out of the hollow fiber membrane from the insertion port of each hollow fiber membrane module 7. Each hollow fiber membrane module 7 is back-washed.

The water level of the processing tank 2 rises by the supply of the processing water from the pressure tank 3 while realizing such an operation. In accordance with this operation, the treated water in the siphon tube 5 also rises, and finally reaches the inverted U-shaped top.
Then, the processing tank 2 communicates with the outside through the siphon tube 5, and all the waste liquid inside is discharged to the outside through the siphon tube 5.

As described above, in the case of the present unit 1, dirt is discharged out of the system by regular backwashing, so that clogging is reduced. In addition, since both the filtering operation and the backwashing operation can be performed by this unit alone without adding another device, the device is low-cost and simple. That is, since it is a backwash water discharge mechanism using the siphon pipe 5 and the pressure tank 3, an apparatus that is simple, low-cost, and has few failures can be realized. Furthermore, the treated water in the pressure tank 3 is
Since the wastewater is discharged and replaced at the time of backwashing, there is no stagnation of treated water, which is convenient for obtaining sterile filtered water.

[System Cleaning Operation] In the case of microfiltration such as the present apparatus, the storage method after the completion of the filtration step is also important.
If the storage method is poor, the hollow fiber membrane module 7 will be contaminated with bacteria and the like, which causes a problem when used the next day. As a countermeasure, after the filtration operation, the mixed solution of the hydrogen peroxide solution and the peracetic acid is poured into the treatment tank 2 so as to be diluted 100 times.

Thereafter, the male part M and the female part F of the one-touch couplers 17 and 18 are removed, and the one-touch coupler 1 is removed.
The male part M of No. 7 and the female part F of the one-touch coupler 18 are connected and circulated and filtered for about 20 minutes, and a mixed solution of hydrogen peroxide and peracetic acid is stored until the next day before the filtering operation.
Then, the next day, before starting the work, the female part F of the tap water for cleaning 16 is connected to the male part M of the one-touch coupler 17, and the female part F of the one-touch coupler 18 is connected to the one-touch coupler 19 attached to the drain pipe 19. Connect to male part M. In such a state, when the tap water for cleaning is distributed,
A mixture of hydrogen peroxide and peracetic acid can be washed away,
And the washing of the whole water treatment system is completed. In the above description, manual operation has been described. However, it is needless to say that switching of the connection relationship of the one-touch coupler and the like may be fully automated.

Example 1 A filtration experiment was performed using raw water having a diatom concentration of about 300 ppm. Using 4 x Stellapore KUX328E (0.1 micron) as the hollow fiber membrane in parallel, pressurizing the primary side (outside) of the hollow fiber membrane module to 5 L / m
When in / one treated water was filtered, the initial pressure difference was doubled in about 30 minutes, and it became impossible to filter in 2 hours. In addition, even if the water pre-filtered with a 1 micron filter is back-flowed and backwashed, although the differential pressure temporarily decreases and the amount of filtered water increases, the amount of filtered water immediately decreases. On the other hand, instead of pressurizing the primary side of the hollow fiber membrane module, a method of suctioning the secondary side (inside) is adopted, and if the same hollow fiber membrane module is used to treat raw water under the same conditions, about 10 times The amount of water flow was obtained.

Example 2 The apparatus shown in FIG. 1 was tested on-site in the 1999 fishing season using water from a papermaking tank. As a result, a comparison between the filtered “papermaking water” and the unfiltered “papermaking water” general bacteria revealed that the number of bacteria before filtration was 1400000, but the number after filtration was 5 or less. Also diatoms,
Tabularia, rigmohola, detritus 5 before filtration
7 mg / liter, 6 mg after filtration
/ Liter.

Although the embodiments of the present invention have been described above, the specific description does not particularly limit the present invention. For example, the device of the embodiment was developed to reduce the number of viable nori bacteria and to improve the quality of laver (shine).
It can also be used in other applications, especially in fields where microfiltration was previously impossible.

As shown in FIG. 3, the bag filters 6a and 6b may have the same structure as the processing tank 2. FIG. 3 shows a state in which a cylindrical filter 6 ′ is detachably attached to the pretreatment tank 31, and the inner cylinder side of the cylindrical filter
3 shows an embodiment in which suction is performed. Here, the cylindrical filter 6 'is formed by winding a filter cloth around an outer peripheral portion of a spring base formed in a coil shape. The operation of the pretreatment tank 31 is the same as the operation of the treatment tank 2. If necessary, the water from the pressure tank 34 flows back into the cylindrical filter 6 ′ of the pretreatment tank 31, and the backflow water flows through the siphon pipe 32. All are drained.

In the case of the previous embodiment, it is necessary to replace or wash the bag filters 6a and 6b every day due to a piece of laver or diatom, but the pretreatment tank 31 as shown in FIG.
If it is provided, it can be used every day without replacing the filter by the automatic backwashing method. Moreover, the cylindrical filter 6 '
Is formed by wrapping a filter cloth around the outer periphery of a spring base formed in a coil shape, so that the spring contracts due to the suction pressure difference during the filtering operation, while the spring returns to its original state during the backwashing operation. The expansion ensures that the filtrate attached to the outside of the filter cloth surface is peeled off.

[0029]

As described above, according to the present invention,
It is possible to realize an inexpensive and simple filtration device and a filtration method that can maintain the performance of the filter member that is easily clogged for a long time and can surely restore the performance by passing water in the reverse direction.

[Brief description of the drawings]

FIG. 1 is a plan view (a), a front view (b), a left side view (c), and a right side view (d), illustrating a microfiltration unit according to the present embodiment.

FIG. 2 is a flowchart showing a use state of the microfiltration unit of FIG. 1;

FIG. 3 is a drawing showing another embodiment of the microfiltration unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Filtration apparatus (precision filtration unit) 2 Processing tank 4 Suction pump 5 Siphon tube 7 Filtration member (hollow fiber membrane filter)

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01D 29/38 510C

Claims (6)

[Claims] 1. A processing tank provided with a filtering member therein for introducing a liquid to be processed, a siphon tube connected to the bottom of the processing tank and rising in an inverted U-shape, and connected to an output side of the filtering member. And a suction pump for sucking the processed liquid. 2. A processing tank provided with a filtering member therein for introducing a liquid to be processed, a siphon tube connected to the bottom of the processing tank and rising in an inverted U-shape, and connected to an output side of the filtering member. A filtering device comprising: a suction pump for sucking a processing liquid to be sucked, a storage tank provided downstream of the suction pump, and an on-off valve provided downstream of the storage tank. 3. The filtering device according to claim 1, wherein the storage tank is a pressure tank that stores a processing liquid while contracting a contractible gas chamber. 4. The filtering device according to claim 1, wherein the filtering member comprises a hollow fiber membrane cartridge or a filter cloth provided on an outer periphery of a coil spring. 5. The filtration device according to claim 1, which is used as a sheet water purifier for laver production. 6. A filtering step in which a filtering member is incorporated and a siphon tube rising in an inverted U-shape is connected to a bottom portion, wherein a water to be treated is constantly sucked from an output side of the filtering member. A step of introducing treated water into the storage tank provided on the downstream side of the processing tank while contracting a gas chamber inside the storage tank, when the filtration member needs to be washed; and Thereafter, the operation of sucking the output side of the filtration member is stopped, and the treated water introduced into the storage tank is
A backwashing step of returning from the output side of the filtration member to the inside of the treatment tank, and raising the water level of the treatment tank to communicate the flow path of the siphon pipe by the backwashing step; And a discharging step of discharging.